IPv6 is enebled by default in Windows 7 and Windows Vista. If you are not using IPv6 then this can be disabled from the Windows Registry as follows:
Click Start – Search and type “regedit” and press enter. This should launch the Registry Editor.
Navigate to the following rgeistry key
In the right-pane, right-click, select New – DWORD Value. Enter the name as “DisabledComponents” and set its value as “FF” as shown below. Once done, restart your system for the changes to take effect. If at a later time you want to revert the changes simply delete the key and reboot your system.